This invention relates to compositions specifically designed to promote the deposition of emollient materials on skin while concurrently performing a cleaning function. More particularly, the invention encompasses liquid detergent compositions especially adapted for dishwashing and other cleaning uses under conditions which involve the immersion of skin in water containing said detergent compositions. The detergent compositions herein enhance the deposition of the emollient on the skin and provide an occlusive film thereon.
The use of emollients in light duty liquid detergents and shampoo compositions is well known. The desirability of compositions which provide an emollient benefit to skin concurrently with a detergent effect has long been recognized, but has been difficult to achieve. The mechanisms of emollient deposition and soil removal are generally in conflict. Emollient materials are usually oily in nature and provide a "load" which substantially detracts from the cleaning and sudsing of detergent compounds. Conversely, the cleaning action of the detergent component of such compositions usually removes oily or waxy emollients from the skin, thereby frustrating the purpose for including such materials in detergent compositions.
By the present invention there are provided liquid detergent compositions comprising an emollient material, an amine oxide and a pH controlling agent. It has been discovered that the use of an amine oxide at an acid pH results in an increase of the lipophilic character of keratinous surfaces such as skin or hair. The increased lipophilic character of the keratinous surface enhances the adsorption of waxy or oily emollients thereon. Accordingly, enhanced deposition of waxy and oily emollients onto surfaces such as skin is achieved by the compositions herein.
Previous efforts have been directed to the formulation of detergent compositions and shampoos containing emollient materials. For example, U.S. Pat. Nos. 2,519,062; 1,674,580 and British Pat. No. 1,054,244 disclose compositions comprising an anionic surfactant and oily or waxy emollient materials. However, the compositions disclosed in these patents are not specifically designed to promote the adsorption of the emollients onto skin in the manner of the present invention.
The use of amine oxides in emollient-containing detergent compositions is suggested in U.S. Pat. No. 3,533,955 and in THE CHEMICAL FORMULARY, Vol. XVI, page 88. An aerosol shaving cream comprising a stearic acid soap, an amine oxide and a silicone fluid is described in THE CHEMICAL FORMULARY, Vol. XVI, page 120. U.S. Pat. No. 3,098,794 relates to hair grooming compositions comprising fatty alcohols and amine oxides. British Pat. No. 1,254,309 discloses shampoos comprising amine oxide conditioning agents. However, none of the foregoing references discloses the use of amine oxides in combination with waterinsoluble emollients and a pH controlling agent capable of maintaining the pH of an aqueous washing medium within the acid range.
Amine oxides are well known for use in detergent compositions; see U.S. Pat. Nos. 3,001,945; 3,223,647; 3,281,368; 3,441,508, 3,441,611; 3,441,612; 3,450,637; and 3,313,734. While these patents suggest the use of amine oxides in conjunction with many of the usual detergent adjuvants, such use is consistently at pH's within the basic range, rather than at the acidic ranges employed in the instant invention. Accordingly, the prior art does not appear to have recognized that amine oxides can be employed under acidic conditions to lipophilize the skin, thereby promoting the adsorption of emollient materials thereto.
It is an object of the present invention to provide liquid detergent compositions which achieve an emollient effect on keratinous surfaces such as skin and hair when employed in an aqueous washing solution.
It is a further object herein to provide emollient detergent compositions specifically adapted to hand dishwashing and hand laundering.
These and other objects are obtained herein as will be seen from the following disclosure.